1. Field of the Invention
This invention relates to a dispensing closure for removable attachment to a dispensing opening of a container. More particularly, this invention relates to a two-piece dispensing closure of the foregoing type with tamper-indicating opening characteristics.
2. Description of the Prior Art
U.S. Pat. No. 4,408,700 (Fillmore et al.), which was assigned to a predecessor of the assignee of the present invention, the disclosure of which is incorporated by reference herein, discloses a two-piece dispensing closure for attachment to the neck of a liquid containing container. The closure of this reference has a molded plastic cap with an annular opening in a top panel portion therein and an annular molded plastic valve telescopically inserted in the opening of the closure panel. The valve is slidable relative to the cap between an inner position of the valve, in which no dispensing of the contents of the container can occur, and an outer position of the valve, in which dispensing of the contents of the container can occur through the valve. Closures of this type have been widely used in the packaging of various non-comestible liquids, such as liquid detergents. and these packaging applications do not require tamper-indicating opening characteristics.
In the packaging of comestible liquids, however, such as sport drinks and other unpressurized beverages, it is desirable to provide a recloseable dispensing closure of the general type of the aforesaid '700 Patent to permit consumption of the contents of the container in doses that are much smaller than the capacity of the container. However, for these applications it is also important that the closure have tamper-indicating opening characteristics, both as to the attachment of the closure cap to the container and as to the telescopic fit between the closure valve and the closure cap, and the aforesaid '700 Patent does not disclose or suggest the inclusion of any structure that would impart the needed tamper-indicating opening characteristics to the closure described therein.
Another requirement for a two-piece dispensing closure for a comestible product is to provide a secure interference fit between the closure valve and the closure cap to prevent inadvertent disengagement of the valve from the cap during movement of the valve from its non-dispensing position to its dispensing position.
Other known prior art references relative to two-piece dispensing closure inventions are U.S. Pat. No. 5,104,008 (Crisci), U.S. Pat. No. 5,588,562 (Sander et al.), U.S. Pat. No. 5,655,685 (Carr et al) and U.S. Pat. No. 5,862,953 (Long, Jr.).